Question

Which term of AP :21,18,15...is-81? Also,in any term 0? Give reason for your answer.

Answer 1

Answer:

term 35 is -81 and 0 is 8th term

Answer 2

Answer:

$\huge\pink{\fbox{\tt{࿐αɴѕωєя࿐}}}$

Here, a = 21, d = 18 – 21 = – 3 and an = – 81, and we have to find n.

As an = a + ( n – 1) d,

we have – 81 = 21 + (n – 1)(– 3)

– 81 = 24 – 3n

– 105 = – 3n

So, n = 35

Therefore, the 35th term of the given AP is – 81.

Next, we want to know if there is any n for which an = 0. If such an n is there, then

21 + (n – 1) (–3) = 0,

i.e., 3(n – 1) = 21

i.e., n = 8

So, the eighth term is 0.

☆ I HOPE ITS HELP YOU ☆